hello. i am going to draw lines around different types of cancer tissue areas that were scanned from a great number of microscopic slides. i have a 49 inch curved computer screen and a very fine trackball device. wonderful. however, this feels cumbersome compared with a 12.9 inch ipad pro and the accompanying pen. it therefore seems important to develop imagej for touch screens. is that being done? looking forward to your comments. many thanks. björn (norway/sweden)

At our institute, we have a couple of workstations with pen screens (running Windows 7), this works well. I don’t know whether it’s equally useful to drive ImageJ with fingers on a touch device (instead of a precise pen), but in any case, this has been discussed in a few other topics here on the forum:

I want to use ImagePlus and ImageProcessor in my Android application for some processing on captured images but ImageJ is dependent on Java AWT which is not supported by Android. Resources state that ImageJ2 has no dependency on AWT but is it complete and does it have the same functionalities (classes and methods) provided by ImageJ? (I need to use ByteProcessor, FloatProcessor methods like isBinary(), resetRoi() and many more). Or else is there any equivalent library in Android which serves the…

I am trying to integrate ImageJ2 library in my Android application because I want to perform image processing on my phone. ImageJ is AWT-based which is why I will be working with ImageJ2. My aim is to replicate the functionalities of Mapir plugin for QGIS in my application. I downloaded the zip file from here: http://imglib2.net/
But I don’t know how to begin. I am new to image processing as well as ImageJ libraries. Can someone kindly list out the steps required to integrate ImageJ2 (ImgLib2) …

Hi @Skien, as far as I am aware, the iPad Pro doesn’t support Java so getting ImageJ to run on it would be… difficult at best. As @imagejan describes, Android seems to be being more actively investigated - but it still sounds like it would be a big job.

I also tried a graphics tablet with a built-in screen for making such annotations, attached to a regular PC/Mac. So this should already be possible with ImageJ. In the end I went back to using a mouse… but maybe I just didn’t stick with it long enough.

In any case, I do my annotations using QuPath (http://qupath.github.io). This was written using JavaFX, and should work with touch screens (but not iPad/Android); you can also customize which touch gestures to turn on, since not all really help*. QuPath also incorporates JPen, which should enable pressure-sensitive drawing if connected to a compatible graphics tablet.

But the most useful feature I find for annotation is the ability to quickly switch between tools in QuPath using shortcut keys (polygon [p], brush [b], wand [w]…), and use additional keys to switch between modes (e.g. hold down the ‘Alt’ key to turn either the brush or wand into an eraser). The brush and wand also adapt according to magnification, so by zooming in or out it’s possible to draw either very detailed or very large and coarse regions using the same tools - and both edit or lock the annotations later as required. Personally, I find that lets me work effectively with a mouse and not really need anything else.

If QuPath supports the kind of files you’re working with, you might want to try it out. It should also be possible to extract the QuPath annotations and put them into an ImageJ-friendly Roi format if needed at the end.

*-When using a Mac and a multitouch mouse or trackpad, I turn on scroll gestures so that I can use scrolling on the mouse to pan around a large image, while scrolling with the Shift key down is used to zoom in and out. But that’s not the default setting, since for a ‘regular’ mouse I think it’s usually more intuitive to link scrolling to zooming directly, and activate a different tool to pan around the image.